[nrf fromtree] Bluetooth: Host: Add API for reading LE controller features

The function supports reading multiple controller-based values.
It is effectively a copy of struct bt_dev_le but in a more
application-oriented definition.

It was chosen to keep the features as an array rather than a
64-bit value, as the comparison macros work on arrays and that
there already exists new bits > 64 in the core spec which is not
yet supported by Zephyr.

It is being smoke tested in a generic GATT client test,
as the individual values may depend on several Kconfig options.

Signed-off-by: Emil Gydesen <[email protected]>
(cherry picked from commit 44c5c1d)

Author: Thalley

doc/releases/release-notes-4.2.rst

@@ -63,6 +63,12 @@ New APIs and options
   like you need to add more details, add them in the API documentation code
   instead.
 
+* Bluetooth
+
+  * Host
+
+    * :c:func:`bt_le_get_local_features`
+
 New Boards
 **********
 

include/zephyr/bluetooth/bluetooth.h

@@ -19,6 +19,7 @@
  */
 
 #include <stdbool.h>
+#include <stdint.h>
 #include <string.h>
 
 #include <zephyr/sys/util.h>
@@ -48,6 +49,13 @@ extern "C" {
  */
 #define BT_ID_DEFAULT 0
 
+/**
+ * @brief Number of octets for local supported
+ *
+ * The value of 8 correspond to page 0 in the LE Controller supported features
+ */
+#define BT_LE_LOCAL_SUPPORTED_FEATURES_SIZE 8
+
 /** Opaque type representing an advertiser. */
 struct bt_le_ext_adv;
 
@@ -517,6 +525,78 @@ size_t bt_data_get_len(const struct bt_data data[], size_t data_count);
  */
 size_t bt_data_serialize(const struct bt_data *input, uint8_t *output);
 
+struct bt_le_local_features {
+	/**
+	 * @brief Local LE controller supported features.
+	 *
+	 * Refer to BT_LE_FEAT_BIT_* for values.
+	 * Refer to the BT_FEAT_LE_* macros for value comparionson.
+	 * See Bluetooth Core Specification, Vol 6, Part B, Section 4.6.
+	 */
+	uint8_t features[BT_LE_LOCAL_SUPPORTED_FEATURES_SIZE];
+
+	/**
+	 * @brief Local LE controller supported states
+	 *
+	 * Refer to BT_LE_STATES_* for values.
+	 * See Bluetooth Core Specification 6.0, Vol 4, Part E, Section 7.8.27
+	 */
+	uint64_t states;
+
+	/**
+	 * @brief ACL data packet length
+	 *
+	 * This represents the maximum ACL HCI Data packet which can be sent from the Host to the
+	 * Controller.
+	 * The Host may support L2CAP and ATT MTUs larger than this value.
+	 * See Bluetooth Core Specification, Vol 6, Part E, Section 7.8.2.
+	 */
+	uint16_t acl_mtu;
+	/** Total number of ACL data packets */
+	uint8_t acl_pkts;
+
+	/**
+	 * @brief ISO data packet length
+	 *
+	 * This represents the maximum ISO HCI Data packet which can be sent from the Host to the
+	 * Controller.
+	 * ISO SDUs above this size can be fragmented assuming that the number of
+	 * @ref bt_le_local_features.iso_pkts support the maximum size.
+	 */
+	uint16_t iso_mtu;
+	/** Total number of ISO data packets */
+	uint8_t iso_pkts;
+
+	/**
+	 * @brief Maximum size of the controller resolving list.
+	 *
+	 * See Bluetooth Core Specification, Vol 6, Part E, Section 7.8.41.
+	 */
+	uint8_t rl_size;
+
+	/**
+	 * @brief Maximum advertising data length
+	 *
+	 * @note The maximum advertising data length also depends on advertising type.
+	 *
+	 * See Bluetooth Core Specification, Vol 6, Part E, Section 7.8.57.
+	 */
+	uint16_t max_adv_data_len;
+};
+
+/**
+ * @brief Get local Bluetooth LE controller features
+ *
+ * Can only be called after bt_enable()
+ *
+ * @param local_features Local features struct to be populated with information.
+ *
+ * @retval 0 Success
+ * @retval -EAGAIN The information is not yet available.
+ * @retval -EINVAL @p local_features is NULL.
+ */
+int bt_le_get_local_features(struct bt_le_local_features *local_features);
+
 /** Advertising options */
 enum {
 	/** Convenience value when no options are specified. */

include/zephyr/bluetooth/hci_types.h

@@ -200,12 +200,14 @@ struct bt_hci_cmd_hdr {
 #define BT_LE_FEAT_BIT_CHANNEL_CLASSIFICATION   39
 #define BT_LE_FEAT_BIT_ADV_CODING_SEL           40
 #define BT_LE_FEAT_BIT_ADV_CODING_SEL_HOST      41
-
+#define BT_LE_FEAT_BIT_DECISION_ADV_FILTER      42
 #define BT_LE_FEAT_BIT_PAWR_ADVERTISER          43
 #define BT_LE_FEAT_BIT_PAWR_SCANNER             44
-
+#define BT_LE_FEAT_BIT_UNSEG_FRAMED_MODE        45
 #define BT_LE_FEAT_BIT_CHANNEL_SOUNDING         46
 #define BT_LE_FEAT_BIT_CHANNEL_SOUNDING_HOST    47
+#define BT_LE_FEAT_BIT_CHANNEL_SOUNDING_TONE_QUAL_IND    48
+#define BT_LE_FEAT_BIT_LL_EXTENDED_FEAT_SET     63
 
 #define BT_LE_FEAT_TEST(feat, n)                (feat[(n) >> 3] & \
 						 BIT((n) & 7))

subsys/bluetooth/host/hci_core.c

@@ -1,12 +1,14 @@
 /* hci_core.c - HCI core Bluetooth handling */
 
 /*
- * Copyright (c) 2017-2021 Nordic Semiconductor ASA
+ * Copyright (c) 2017-2025 Nordic Semiconductor ASA
  * Copyright (c) 2015-2016 Intel Corporation
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#include <zephyr/autoconf.h>
+
 #include <zephyr/bluetooth/hci_types.h>
 #include <zephyr/kernel.h>
 #include <string.h>
@@ -4509,6 +4511,29 @@ int bt_set_appearance(uint16_t appearance)
 }
 #endif
 
+int bt_le_get_local_features(struct bt_le_local_features *remote_info)
+{
+	if (remote_info == NULL) {
+		return -EINVAL;
+	}
+
+	if (!atomic_test_bit(bt_dev.flags, BT_DEV_READY)) {
+		return -EAGAIN;
+	}
+
+	memcpy(remote_info->features, bt_dev.le.features, sizeof(remote_info->features));
+	remote_info->states = bt_dev.le.states;
+	remote_info->acl_mtu = COND_CODE_1(CONFIG_BT_CONN, (bt_dev.le.acl_mtu), (0));
+	remote_info->acl_pkts = COND_CODE_1(CONFIG_BT_CONN, (bt_dev.le.acl_pkts.limit), (0));
+	remote_info->iso_mtu = COND_CODE_1(CONFIG_BT_ISO, (bt_dev.le.iso_mtu), (0));
+	remote_info->iso_pkts = COND_CODE_1(CONFIG_BT_ISO, (bt_dev.le.iso_limit), (0));
+	remote_info->rl_size = COND_CODE_1(CONFIG_BT_SMP, (bt_dev.le.rl_size), (0));
+	remote_info->max_adv_data_len =
+		COND_CODE_1(CONFIG_BT_BROADCASTER, (bt_dev.le.max_adv_data_len), (0));
+
+	return 0;
+}
+
 bool bt_addr_le_is_bonded(uint8_t id, const bt_addr_le_t *addr)
 {
 	if (IS_ENABLED(CONFIG_BT_SMP)) {

subsys/bluetooth/host/hci_core.h

@@ -1,12 +1,14 @@
 /* hci_core.h - Bluetooth HCI core access */
 
 /*
- * Copyright (c) 2021 Nordic Semiconductor ASA
+ * Copyright (c) 2021-2025 Nordic Semiconductor ASA
  * Copyright (c) 2015-2016 Intel Corporation
  *
  * SPDX-License-Identifier: Apache-2.0
  */
+#include <stdint.h>
 
+#include <zephyr/bluetooth/bluetooth.h>
 #include <zephyr/devicetree.h>
 
 /* LL connection parameters */
@@ -271,7 +273,7 @@ struct bt_le_per_adv_sync {
 
 struct bt_dev_le {
 	/* LE features */
-	uint8_t			features[8];
+	uint8_t features[BT_LE_LOCAL_SUPPORTED_FEATURES_SIZE];
 	/* LE states */
 	uint64_t			states;
 

tests/bsim/bluetooth/host/gatt/general/src/gatt_client_test.c

@@ -6,6 +6,7 @@
 
 #include <zephyr/kernel.h>
 
+#include <zephyr/sys/byteorder.h>
 #include <zephyr/types.h>
 #include <stddef.h>
 #include <errno.h>
@@ -363,6 +364,7 @@ static void gatt_read(uint16_t handle, uint8_t expect_att_err)
 
 static void test_main(void)
 {
+	struct bt_le_local_features local_features;
 	int err;
 
 	bt_conn_cb_register(&conn_callbacks);
@@ -372,6 +374,13 @@ static void test_main(void)
 		TEST_FAIL("Bluetooth discover failed (err %d)", err);
 	}
 
+	err = bt_le_get_local_features(&local_features);
+	TEST_ASSERT(err == 0, "Failed to get local features");
+	TEST_ASSERT(local_features.acl_mtu > 0U, "Invalid ACL MTU");
+	TEST_ASSERT(local_features.acl_pkts > 0U, "Invalid ACL packet count");
+	TEST_ASSERT(sys_get_le64(local_features.features) > 0U, "Invalid features");
+	TEST_ASSERT(local_features.states > 0U, "Invalid states");
+
 	err = bt_le_scan_start(BT_LE_SCAN_PASSIVE, device_found);
 	if (err != 0) {
 		TEST_FAIL("Scanning failed to start (err %d)", err);